Assess model bias. The Jarque-Bera statistic indicates whether or not the residuals (the observed/known dependent variable values minus the predicted/estimated values) are normally distributed. The null hypothesis for this test is that the residuals are normally distributed and so if you were to construct a histogram of those residuals, they would resemble the classic bell curve, or Gaussian distribution. When the p-value (probability) for this test is small (is smaller than 0.05 for a 95% confidence level, for example), the residuals are not normally distributed, indicating model misspecification (a key variable is missing from the model). Results from a misspecified OLS model are not trustworthy.